A bgv-type multi-key fully homomorphic encryption method

Abstract

The present invention specifically relates to an efficient BGV-type multi-key fully homomorphic encryption method, comprising: performing BGV-type homomorphic encryption on the plaintext of a user participating in the operation to obtain the ciphertext corresponding to the user; The ciphertext is expanded to obtain the extended ciphertext of the corresponding user set; the homomorphic operation is performed on the extended ciphertext of the user set participating in the operation to obtain a high-dimensional BGV ciphertext, and the BGV synchronization is performed on the keys of the users participating in the calculation. State encryption and GSW homomorphic encryption, and perform ciphertext expansion and mixed homomorphic multiplication on the encrypted result to obtain the calculation key, and reduce the dimensionality of the high-dimensional BGV ciphertext through the calculation key; The ciphertext runs the modulus function to reduce the noise in the ciphertext, and finally outputs the final ciphertext result of the homomorphic operation. The BGV-type multi-key fully homomorphic encryption method can allow homomorphic operations between ciphertexts of users with different keys, thereby realizing a secure multi-party computing function.

Description

technical field [0001] The invention belongs to the field of information security and privacy protection, and in particular relates to an efficient BGV type multi-key fully homomorphic encryption method. Background technique [0002] Fully homomorphic encryption (Full-homomorphic encryption, FHE) can perform arbitrary calculations on ciphertexts when the key is unknown. It has the property of exchanging encryption and operations, and has a high theoretical and application level in the current cloud computing environment. Value, can be widely used in ciphertext retrieval, secure multi-party computing, cloud data analysis, etc. Since Gentry proposed the first ideal lattice-based fully homomorphic encryption scheme Gen09 in 2009, based on Gentry's blueprint for fully homomorphic encryption, more and more fully homomorphic encryption schemes (DGHV10, BV11a, BV11b, BGV12 , GSW13, AP14, etc.) were proposed. [0003] Multi-key fully homomorphic encryption (multi-key FHE, MKFHE) a...

AI Technical Summary

Problems solved by technology

The BGV-type MKFHE scheme has the disadvantages of large amount of ciphertext, relatively large public parameters, and a large amount of computation in the process of generating and calculating keys

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